unicode-math (9oct17)

git-svn-id: svn://tug.org/texlive/trunk@45510 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 590 insertions, 0 deletions

diff --git a/Master/texmf-dist/source/latex/unicode-math/unicode-math-main.dtx b/Master/texmf-dist/source/latex/unicode-math/unicode-math-main.dtx
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+
+% \section{\DTXCURR --- The main \cs{setmathfont} macro}
+%
+%    \begin{macrocode}
+%<*package&(XE|LU)>
+%    \end{macrocode}
+%
+% Using a |range| including large character sets such as \cmd\mathrel,
+% \cmd\mathalpha, \etc, is \emph{very slow}!
+% I hope to improve the performance somehow.
+%
+% \begin{macro}{\setmathfont}
+% \doarg{font features (first optional argument retained for backwards compatibility)}
+% \darg{font name}
+% \doarg{font features}
+%    \begin{macrocode}
+\DeclareDocumentCommand \setmathfont { O{} m O{} }
+  {
+    \@@_setmathfont:nn {#1,#3} {#2}
+  }
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\cs_set:Nn \@@_setmathfont:nn
+ {
+  \tl_set:Nn \l_@@_fontname_tl {#2}
+  \@@_init:
+%    \end{macrocode}
+% Grab the current size information:
+% (is this robust enough? Maybe it should be preceded by \cmd\normalsize).
+% The macro \cmd\S@\meta{size}
+% contains the definitions of the sizes used for maths letters, subscripts and subsubscripts in
+% \cmd\tf@size, \cmd\sf@size, and \cmd\ssf@size, respectively.
+%    \begin{macrocode}
+  \cs_if_exist:cF { S@ \f@size } { \calculate@math@sizes }
+  \csname S@\f@size\endcsname
+%    \end{macrocode}
+% Parse options and tell people what's going on:
+%    \begin{macrocode}
+  \keys_set_known:nnN {unicode-math} {#1} \l_@@_unknown_keys_clist
+  \bool_if:NT \l_@@_init_bool { \@@_log:n {default-math-font} }
+%    \end{macrocode}
+% Use \pkg{fontspec} to select a font to use.
+% After loading the font, we detect what sizes it recommends for scriptsize and scriptscriptsize, so after setting those values appropriately, we reload the font to take these into account.
+%    \begin{macrocode}
+%<debug>  \csname TIC\endcsname
+  \@@_fontspec_select_font:
+%<debug>  \csname TOC\endcsname
+  \bool_if:nT { \l_@@_ot_math_bool && !\g_@@_mainfont_already_set_bool }
+   {
+    \@@_declare_math_sizes:
+    \@@_fontspec_select_font:
+   }
+%    \end{macrocode}
+% Now define |\@@_symfont_tl| as the \LaTeX\ math font to access everything:
+%    \begin{macrocode}
+  \cs_if_exist:cF { sym \@@_symfont_tl }
+    {
+      \DeclareSymbolFont{\@@_symfont_tl}
+        {\encodingdefault}{\l_@@_family_tl}{\mddefault}{\updefault}
+    }
+  \SetSymbolFont{\@@_symfont_tl}{\l_@@_mversion_tl}
+    {\encodingdefault}{\l_@@_family_tl}{\mddefault}{\updefault}
+%    \end{macrocode}
+% Set the bold math version.
+%    \begin{macrocode}
+  \str_if_eq_x:nnT {\l_@@_mversion_tl} {normal}
+    {
+     \SetSymbolFont{\@@_symfont_tl}{bold}
+      {\encodingdefault}{\l_@@_family_tl}{\bfdefault}{\updefault}
+    }
+%    \end{macrocode}
+% Declare the math sizes (i.e., scaling of superscripts) for the specific
+% values for this font,
+% and set defaults for math fams two and three for legacy compatibility:
+%    \begin{macrocode}
+  \bool_if:nT { \l_@@_ot_math_bool && !\g_@@_mainfont_already_set_bool }
+   {
+    \bool_set_true:N \g_@@_mainfont_already_set_bool
+    \@@_setup_legacy_fam_two:
+    \@@_setup_legacy_fam_three:
+   }
+%    \end{macrocode}
+% And now we input every single maths char.
+%    \begin{macrocode}
+%<debug>  \csname TIC\endcsname
+  \@@_input_math_symbol_table:
+%<debug>  \csname TOC\endcsname
+%    \end{macrocode}
+% Finally,
+% \begin{itemize}
+% \item Remap symbols that don't take their natural mathcode
+% \item Activate any symbols that need to be math-active
+% \item Enable wide/narrow accents
+% \item Assign delimiter codes for symbols that need to grow
+% \item Setup the maths alphabets (\cs{mathbf} etc.).
+%       This is an extensive part of the code; see Section~\ref{sec:mathmap}.
+% \item Setup negations, which are handled on an ad hoc basis; see Section~\ref{sec:negations}.
+% \end{itemize}
+%    \begin{macrocode}
+  \@@_remap_symbols:
+  \@@_setup_mathactives:
+  \@@_setup_delcodes:
+%<debug>  \csname TIC\endcsname
+  \@@_setup_alphabets:
+%<debug>  \csname TOC\endcsname
+  \@@_setup_negations:
+ }
+%    \end{macrocode}
+% \end{macro}
+%
+% \paragraph{Fall-back font}
+%
+% Want to load Latin Modern Math if nothing else.
+% This needs to happen early so that all of the font-loading machinery executes before
+% the other `AtBeginDocument' code.
+%    \begin{macrocode}
+\AtBeginDocument { \@@_load_lm_if_necessary: }
+\cs_new:Nn \@@_load_lm_if_necessary:
+  {
+    \cs_if_exist:NF \l_@@_fontname_tl
+      {
+        % TODO: update this when lmmath-bold.otf is released
+        \setmathfont{latinmodern-math.otf}[BoldFont={latinmodern-math.otf}]
+        \bool_set_false:N \g_@@_mainfont_already_set_bool
+      }
+  }
+%    \end{macrocode}
+% Note that here we reset the `font already loaded' boolean so that a new font being set
+% will do the right thing in terms of setting up defaults.
+%
+% TODO: need a better way to do this for the general case. (Maybe a `reset' command option?)
+%
+% \begin{macro}{\@@_init:}
+%    \begin{macrocode}
+\cs_new:Nn \@@_init:
+ {
+%    \end{macrocode}
+% \begin{itemize}
+% \item Initially assume we're using a proper OpenType font with unicode maths.
+%    \begin{macrocode}
+  \bool_set_true:N  \l_@@_ot_math_bool
+%    \end{macrocode}
+% \item Erase any conception \LaTeX\ has of previously defined math symbol fonts;
+% this allows \cmd\DeclareSymbolFont\ at any point in the document.
+%    \begin{macrocode}
+  \cs_set_eq:NN \glb@currsize \scan_stop:
+%    \end{macrocode}
+% \item To start with, assume we're defining the font for every math symbol character.
+%    \begin{macrocode}
+  \bool_set_true:N \l_@@_init_bool
+  \seq_clear:N \l_@@_char_range_seq
+  \clist_clear:N \l_@@_char_nrange_clist
+  \seq_clear:N \l_@@_mathalph_seq
+  \seq_clear:N \l_@@_missing_alph_seq
+%    \end{macrocode}
+% \item By default use the `normal' math version.
+%    \begin{macrocode}
+  \tl_set:Nn \l_@@_mversion_tl {normal}
+%    \end{macrocode}
+% \item Other range initialisations.
+%    \begin{macrocode}
+  \tl_set:Nn \@@_symfont_tl {operators}
+  \cs_set_eq:NN \_@@_sym:nnn \@@_process_symbol_noparse:nnn
+  \cs_set_eq:NN \@@_set_mathalphabet_char:nnn \@@_mathmap_noparse:nnn
+  \cs_set_eq:NN \@@_remap_symbol:nnn \@@_remap_symbol_noparse:nnn
+  \cs_set_eq:NN \@@_maybe_init_alphabet:n \@@_init_alphabet:n
+  \cs_set_eq:NN \@@_map_char_single:nn \@@_map_char_noparse:nn
+  \cs_set_eq:NN \@@_assign_delcode:nn \@@_assign_delcode_noparse:nn
+  \cs_set_eq:NN \@@_make_mathactive:nNN \@@_make_mathactive_noparse:nNN
+%    \end{macrocode}
+% \item Define default font features for the script and scriptscript font.
+%    \begin{macrocode}
+  \tl_set:Nn \l_@@_script_features_tl  {Style=MathScript}
+  \tl_set:Nn \l_@@_sscript_features_tl {Style=MathScriptScript}
+  \tl_set_eq:NN \l_@@_script_font_tl   \l_@@_fontname_tl
+  \tl_set_eq:NN \l_@@_sscript_font_tl  \l_@@_fontname_tl
+%    \end{macrocode}
+% \end{itemize}
+%    \begin{macrocode}
+ }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_declare_math_sizes:}
+% Set the math sizes according to the recommended font parameters.
+% TODO: this shouldn't need to be per-engine; check out why the wrappers aren't used.
+%    \begin{macrocode}
+\cs_new:Nn \@@_declare_math_sizes:
+  {
+%<*LU>
+    \fp_compare:nF { \@@_script_style_size:n {ScriptPercentScaleDown} == 0 }
+      {
+        \DeclareMathSizes { \f@size } { \f@size }
+          { \@@_script_style_size:n {ScriptPercentScaleDown} }
+          { \@@_script_style_size:n {ScriptScriptPercentScaleDown} }
+      }
+%</LU>
+%<*XE>
+    \dim_compare:nF { \fontdimen 10 \l_@@_font == 0pt }
+      {
+        \DeclareMathSizes { \f@size } { \f@size }
+          { \@@_fontdimen_to_scale:nn {10} {\l_@@_font} }
+          { \@@_fontdimen_to_scale:nn {11} {\l_@@_font} }
+      }
+%</XE>
+  }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_script_style_size:n}
+% Determine script- and scriptscriptstyle sizes using luaotfload:
+%   \begin{macrocode}
+%<*LU>
+\cs_new:Nn \@@_script_style_size:n
+  {
+    \fp_eval:n {\directlua{tex.sprint(luaotfload.aux.get_math_dimension("l_@@_font","#1"))} * \f@size / 100 }
+  }
+%</LU>
+%   \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_setup_legacy_fam_two:}
+% \TeX\ won't load the same font twice at the same scale, so we need to magnify this one by an imperceptable amount.
+%    \begin{macrocode}
+\cs_new:Nn \@@_setup_legacy_fam_two:
+  {
+    \fontspec_set_family:Nxn \l_@@_family_tl
+      {
+      \l_@@_font_keyval_tl,
+      Scale=1.00001,
+      FontAdjustment =
+       {
+        \fontdimen8\font= \@@_get_fontparam:nn {43} {FractionNumeratorDisplayStyleShiftUp}\relax
+        \fontdimen9\font= \@@_get_fontparam:nn {42} {FractionNumeratorShiftUp}\relax
+        \fontdimen10\font=\@@_get_fontparam:nn {32} {StackTopShiftUp}\relax
+        \fontdimen11\font=\@@_get_fontparam:nn {45} {FractionDenominatorDisplayStyleShiftDown}\relax
+        \fontdimen12\font=\@@_get_fontparam:nn {44} {FractionDenominatorShiftDown}\relax
+        \fontdimen13\font=\@@_get_fontparam:nn {21} {SuperscriptShiftUp}\relax
+        \fontdimen14\font=\@@_get_fontparam:nn {21} {SuperscriptShiftUp}\relax
+        \fontdimen15\font=\@@_get_fontparam:nn {22} {SuperscriptShiftUpCramped}\relax
+        \fontdimen16\font=\@@_get_fontparam:nn {18} {SubscriptShiftDown}\relax
+        \fontdimen17\font=\@@_get_fontparam:nn {18} {SubscriptShiftDownWithSuperscript}\relax
+        \fontdimen18\font=\@@_get_fontparam:nn {24} {SuperscriptBaselineDropMax}\relax
+        \fontdimen19\font=\@@_get_fontparam:nn {20} {SubscriptBaselineDropMin}\relax
+        \fontdimen20\font=0pt\relax % delim1 = FractionDelimiterDisplaySize
+        \fontdimen21\font=0pt\relax % delim2 = FractionDelimiterSize
+        \fontdimen22\font=\@@_get_fontparam:nn {15} {AxisHeight}\relax
+       }
+      } {\l_@@_fontname_tl}
+
+    \SetSymbolFont{symbols}{\l_@@_mversion_tl}
+      {\encodingdefault}{\l_@@_family_tl}{\mddefault}{\updefault}
+
+    \str_if_eq_x:nnT {\l_@@_mversion_tl} {normal}
+      {
+      \SetSymbolFont{symbols}{bold}
+        {\encodingdefault}{\l_@@_family_tl}{\bfdefault}{\updefault}
+      }
+  }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_setup_legacy_fam_three:}
+% Similarly, this font is shrunk by an imperceptable amount for \TeX\ to load it again.
+%    \begin{macrocode}
+\cs_new:Nn \@@_setup_legacy_fam_three:
+  {
+    \fontspec_set_family:Nxn \l_@@_family_tl
+      {
+      \l_@@_font_keyval_tl,
+      Scale=0.99999,
+      FontAdjustment={
+        \fontdimen8\font= \@@_get_fontparam:nn {48} {FractionRuleThickness}\relax
+        \fontdimen9\font= \@@_get_fontparam:nn {28} {UpperLimitGapMin}\relax
+        \fontdimen10\font=\@@_get_fontparam:nn {30} {LowerLimitGapMin}\relax
+        \fontdimen11\font=\@@_get_fontparam:nn {29} {UpperLimitBaselineRiseMin}\relax
+        \fontdimen12\font=\@@_get_fontparam:nn {31} {LowerLimitBaselineDropMin}\relax
+        \fontdimen13\font=0pt\relax
+      }
+    } {\l_@@_fontname_tl}
+
+    \SetSymbolFont{largesymbols}{\l_@@_mversion_tl}
+      {\encodingdefault}{\l_@@_family_tl}{\mddefault}{\updefault}
+
+    \str_if_eq_x:nnT {\l_@@_mversion_tl} {normal}
+      {
+      \SetSymbolFont{largesymbols}{bold}
+        {\encodingdefault}{\l_@@_family_tl}{\bfdefault}{\updefault}
+      }
+  }
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\cs_new:Nn \@@_get_fontparam:nn
+  {
+%<XE>    \the\fontdimen#1\l_@@_font\relax
+%<LU>    \directlua{fontspec.mathfontdimen("l_@@_font","#2")}
+  }
+%    \end{macrocode}
+%
+% \begin{macro}{\@@_fontspec_select_font:}
+% Select the font with \cs{fontspec} and define \cs{l_@@_font} from it.
+%    \begin{macrocode}
+\cs_new:Nn \@@_fontspec_select_font:
+ {
+  \tl_set:Nx \l_@@_font_keyval_tl {
+%<LU>     Renderer = Basic,
+    BoldItalicFont = {}, ItalicFont = {},
+    Script = Math,
+    SizeFeatures =
+     {
+      {
+       Size = \tf@size-
+      } ,
+      {
+       Size = \sf@size-\tf@size ,
+       Font = \l_@@_script_font_tl ,
+       \l_@@_script_features_tl
+      } ,
+      {
+       Size = -\sf@size ,
+       Font = \l_@@_sscript_font_tl ,
+       \l_@@_sscript_features_tl
+      }
+     } ,
+    \l_@@_unknown_keys_clist
+  }
+  \fontspec_set_fontface:NNxn \l_@@_font \l_@@_family_tl
+    {\l_@@_font_keyval_tl} {\l_@@_fontname_tl}
+%    \end{macrocode}
+% Check whether we're using a real maths font:
+%    \begin{macrocode}
+  \group_begin:
+    \fontfamily{\l_@@_family_tl}\selectfont
+    \fontspec_if_script:nF {math} {\bool_gset_false:N \l_@@_ot_math_bool}
+  \group_end:
+ }
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{Functions for setting up symbols with mathcodes}
+% \seclabel{mathsymbol}
+%
+% \begin{macro}{\@@_process_symbol_noparse:nnn}
+% \begin{macro}{\@@_process_symbol_parse:nnn}
+% If the \feat{range} font feature has been used, then only
+% a subset of the Unicode glyphs are to be defined.
+% See \secref{rangeproc} for the code that enables this.
+%    \begin{macrocode}
+\cs_set:Nn \@@_process_symbol_noparse:nnn
+ {
+  \@@_set_mathsymbol:nNNn {\@@_symfont_tl} #2 #3 {#1}
+ }
+%    \end{macrocode}
+%    \begin{macrocode}
+\cs_set:Nn \@@_process_symbol_parse:nnn
+ {
+  \@@_if_char_spec:nNNT {#1} {#2} {#3}
+   {
+    \@@_process_symbol_noparse:nnn {#1} {#2} {#3}
+   }
+ }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_remap_symbols:}
+% \begin{macro}{\@@_remap_symbol_noparse:nnn}
+% \begin{macro}{\@@_remap_symbol_parse:nnn}
+% This function is used to define the mathcodes for those chars which should
+% be mapped to a different glyph than themselves.
+%    \begin{macrocode}
+\cs_new:Npn \@@_remap_symbols:
+ {
+  \@@_remap_symbol:nnn{`\-}{\mathbin}{"02212}% hyphen to minus
+  \@@_remap_symbol:nnn{`\*}{\mathbin}{"02217}% text asterisk to "centred asterisk"
+  \bool_if:NF \g_@@_literal_colon_bool
+   {
+    \@@_remap_symbol:nnn{`\:}{\mathrel}{"02236}% colon to ratio (i.e., punct to rel)
+   }
+ }
+%    \end{macrocode}
+% \end{macro}
+% Where |\@@_remap_symbol:nnn| is defined to be one of these two, depending
+% on the range setup:
+%    \begin{macrocode}
+\cs_new:Nn \@@_remap_symbol_parse:nnn
+ {
+  \@@_if_char_spec:nNNT {#3} {\@nil} {#2}
+   { \@@_remap_symbol_noparse:nnn {#1} {#2} {#3} }
+ }
+\cs_new:Nn \@@_remap_symbol_noparse:nnn
+ {
+  \clist_map_inline:nn {#1}
+   { \@@_set_mathcode:nnnn {##1} {#2} {\@@_symfont_tl} {#3} }
+ }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{Active math characters}
+%
+% There are more math active chars later in the subscript/superscript section.
+% But they don't need to be able to be typeset directly.
+%
+% \begin{macro}{\@@_setup_mathactives:}
+%    \begin{macrocode}
+\cs_new:Npn \@@_setup_mathactives:
+ {
+  \@@_make_mathactive:nNN {"2032} \@@_prime_single_mchar \mathord
+  \@@_make_mathactive:nNN {"2033} \@@_prime_double_mchar \mathord
+  \@@_make_mathactive:nNN {"2034} \@@_prime_triple_mchar \mathord
+  \@@_make_mathactive:nNN {"2057} \@@_prime_quad_mchar   \mathord
+  \@@_make_mathactive:nNN {"2035} \@@_backprime_single_mchar \mathord
+  \@@_make_mathactive:nNN {"2036} \@@_backprime_double_mchar \mathord
+  \@@_make_mathactive:nNN {"2037} \@@_backprime_triple_mchar \mathord
+  \@@_make_mathactive:nNN {`\'} \mathstraightquote \mathord
+  \@@_make_mathactive:nNN {`\`} \mathbacktick      \mathord
+ }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_make_mathactive:nNN}
+% Makes |#1| a mathactive char, and gives cs |#2| the meaning of mathchar |#1|
+% with class |#3|.
+% You are responsible for giving active |#1| a particular meaning!
+%    \begin{macrocode}
+\cs_new:Nn \@@_make_mathactive_parse:nNN
+  {
+    \@@_if_char_spec:nNNT {#1} #2 #3
+      { \@@_make_mathactive_noparse:nNN {#1} #2 #3 }
+  }
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\cs_new:Nn \@@_make_mathactive_noparse:nNN
+  {
+    \@@_set_mathchar:NNnn #2 #3 {\@@_symfont_tl} {#1}
+    \@@_char_gmake_mathactive:n {#1}
+  }
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{Delimiter codes}
+%
+% \begin{macro}{\@@_assign_delcode:nn}
+%    \begin{macrocode}
+\cs_new:Nn \@@_assign_delcode_noparse:nn
+ {
+  \@@_set_delcode:nnn \@@_symfont_tl {#1} {#2}
+ }
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\cs_new:Nn \@@_assign_delcode_parse:nn
+ {
+  \@@_if_char_spec:nNNT {#2} {\@nil} {\@nil}
+   {
+    \@@_assign_delcode_noparse:nn {#1} {#2}
+   }
+ }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_assign_delcode:n}
+% Shorthand.
+%    \begin{macrocode}
+\cs_new:Nn \@@_assign_delcode:n { \@@_assign_delcode:nn {#1} {#1} }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_setup_delcodes:}
+% Some symbols that aren't mathopen/mathclose still need to have delimiter codes assigned.
+% The list of vertical arrows may be incomplete.
+% On the other hand, many fonts won't support them all being stretchy.
+% And some of them are probably not meant to stretch, either. But adding them here doesn't hurt.
+%    \begin{macrocode}
+\cs_new:Npn \@@_setup_delcodes:
+ {
+  % ensure \left. and \right. work:
+  \@@_set_delcode:nnn \@@_symfont_tl {`\.} {\c_zero}
+  % this is forcefully done to fix a bug -- indicates a larger problem!
+
+  \@@_assign_delcode:nn {`\/}   {\g_@@_slash_delimiter_usv}
+  \@@_assign_delcode:nn {"2044} {\g_@@_slash_delimiter_usv} % fracslash
+  \@@_assign_delcode:nn {"2215} {\g_@@_slash_delimiter_usv} % divslash
+  \@@_assign_delcode:n {"005C} % backslash
+  \@@_assign_delcode:nn {`\<} {"27E8} % angle brackets with ascii notation
+  \@@_assign_delcode:nn {`\>} {"27E9} % angle brackets with ascii notation
+  \@@_assign_delcode:n {"2191} % up arrow
+  \@@_assign_delcode:n {"2193} % down arrow
+  \@@_assign_delcode:n {"2195} % updown arrow
+  \@@_assign_delcode:n {"219F} % up arrow twohead
+  \@@_assign_delcode:n {"21A1} % down arrow twohead
+  \@@_assign_delcode:n {"21A5} % up arrow from bar
+  \@@_assign_delcode:n {"21A7} % down arrow from bar
+  \@@_assign_delcode:n {"21A8} % updown arrow from bar
+  \@@_assign_delcode:n {"21BE} % up harpoon right
+  \@@_assign_delcode:n {"21BF} % up harpoon left
+  \@@_assign_delcode:n {"21C2} % down harpoon right
+  \@@_assign_delcode:n {"21C3} % down harpoon left
+  \@@_assign_delcode:n {"21C5} % arrows up down
+  \@@_assign_delcode:n {"21F5} % arrows down up
+  \@@_assign_delcode:n {"21C8} % arrows up up
+  \@@_assign_delcode:n {"21CA} % arrows down down
+  \@@_assign_delcode:n {"21D1} % double up arrow
+  \@@_assign_delcode:n {"21D3} % double down arrow
+  \@@_assign_delcode:n {"21D5} % double updown arrow
+  \@@_assign_delcode:n {"21DE} % up arrow double stroke
+  \@@_assign_delcode:n {"21DF} % down arrow double stroke
+  \@@_assign_delcode:n {"21E1} % up arrow dashed
+  \@@_assign_delcode:n {"21E3} % down arrow dashed
+  \@@_assign_delcode:n {"21E7} % up white arrow
+  \@@_assign_delcode:n {"21E9} % down white arrow
+  \@@_assign_delcode:n {"21EA} % up white arrow from bar
+  \@@_assign_delcode:n {"21F3} % updown white arrow
+ }
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{(Big) operators}
+%
+% The engine does what is necessary to deal with big operators for us
+% automatically with \cmd\Umathchardef.
+% However, the limits aren't set automatically; that is, we want to define,
+% a la Plain \TeX\ \etc, |\def\int{\intop\nolimits}|, so there needs to be a
+% transformation from \cmd\int\ to \cmd\intop\ during the expansion of
+% \cmd\_@@_sym:nnn\ in the appropriate contexts.
+%
+% \begin{macro}{\l_@@_nolimits_tl}
+% This macro is a sequence containing those maths operators that require a
+% \cmd\nolimits\ suffix.
+% This list is used when processing |unicode-math-table.tex| to define such
+% commands automatically (see the macro \cs{@@_set_mathsymbol:nNNn}).
+% I've chosen essentially just the operators that look like integrals;
+% hopefully a better mathematician can help me out here.
+% I've a feeling that it's more useful \emph{not} to include the multiple
+% integrals such as $\iiiint$, but that might be a matter of preference.
+%    \begin{macrocode}
+\tl_set:Nn \l_@@_nolimits_tl
+ {
+  \int\iint\iiint\iiiint\oint\oiint\oiiint
+  \intclockwise\varointclockwise\ointctrclockwise\sumint
+  \intbar\intBar\fint\cirfnint\awint\rppolint
+  \scpolint\npolint\pointint\sqint\intlarhk\intx
+  \intcap\intcup\upint\lowint
+ }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\addnolimits}
+% This macro appends material to the macro containing the list of operators
+% that don't take limits.
+%    \begin{macrocode}
+\DeclareDocumentCommand \addnolimits {m}
+ {
+  \tl_put_right:Nn \l_@@_nolimits_tl {#1}
+ }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\removenolimits}
+% Can this macro be given a better name?
+% It removes an item from the nolimits list.
+%    \begin{macrocode}
+\DeclareDocumentCommand \removenolimits {m}
+ {
+  \tl_remove_all:Nn \l_@@_nolimits_tl {#1}
+ }
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{Radicals}
+%
+% \begin{macro}{\l_@@_radicals_tl}
+% The radicals are organised in \cs{@@_set_mathsymbol:nNNn}.
+% We organise radicals in the same way as nolimits-operators.
+% (\cs{cuberoot} and \cs{fourthroot}, don't seem to behave as proper radicals.)
+%    \begin{macrocode}
+\tl_set:Nn \l_@@_radicals_tl {\sqrt \longdivision}
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+%</package&(XE|LU)>
+%    \end{macrocode}
+%
+\endinput